Japanese unexamined utility model application publication No. H02-40541 (See FIG. 2, Patent Document 1) and Japanese unexamined patent application publication No. 2004-45795 (See FIG. 6, Patent Document 2) describe related art image forming apparatuses. For example, the related art image forming apparatuses include a photosensitive member and a light-emitting surface of an exposure member (such as an LED head), and the photosensitive member and the light-emitting surface are disposed close to each other to expose the photosensitive member. In the related art image forming apparatuses, since the photosensitive member and the light-emitting surface of the exposure member are disposed close to each other, a developer floating from a developing unit supplying the developer to the photosensitive member is attached to the light-emitting surface to contaminate the light-emitting surface, thereby deteriorating the quality of image. Therefore, for example, Patent Document 1 or Patent Document 2 discloses a configuration in which a dust-proof wall or a shielding portion protruding toward the photosensitive member is disposed in the vicinity of the end (light-emitting surface) of the exposure member to prevent the developer floating from the developing unit from being attached to the light-emitting surface.